Thermistor flow path

ABSTRACT

A fluid pump includes a pump element in communication with an inlet and an outlet. Rotation of the pump element generates a suction at the inlet and pressure at the outlet. The suction and pressure cooperate to move a fluid through a fluid path. An accessory fluid path is in communication with the inlet and outlet. The accessory fluid path includes a thermistor in communication with the accessory fluid path. The thermistor monitors a temperature of the fluid within the accessory fluid path.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/342,615, filed onMay 27, 2016, entitled “THERMISTOR FLOW PATH,” the entire disclosure ofwhich is hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to fluid pumps, and morespecifically, fluid pumps with a temperature sensing mechanism.

BACKGROUND OF THE INVENTION

Fluid pumps can be included within various fluid reservoirs for moving afluid from within the reservoir to within another portion of themechanism. Such pumps are configured to be submerged within thereservoir.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a fluid pump includesa pump element in communication with an inlet and an outlet. Rotation ofthe pump element generates a suction at the inlet and pressure at theoutlet. The suction and pressure cooperate to move a fluid through afluid path. An accessory fluid path is in communication with the inletand outlet. The accessory fluid path includes a thermistor incommunication with the accessory fluid path. The thermistor monitors atemperature of the fluid within the accessory fluid path.

According to another aspect of the present invention, a fluid pumpincludes a pump element in communication with a fluid path. An accessoryfluid path defines a portion of the fluid path. A shadow port is incommunication with the pump element, wherein the pump element and theshadow port regulate a flow of a fluid between a primary flow of thefluid to an outlet. An excess flow of the fluid to the accessory fluidpath, wherein operation of the pump element in conjunction with theshadow port, promotes the primary flow of the fluid toward the outletand simultaneously promotes the excess flow of the fluid through theaccessory fluid path. The excess flow of the fluid through the accessoryfluid path directly engages a thermistor disposed within the accessoryfluid path. The thermistor measures a fluid temperature of the excessflow of the fluid within the accessory fluid path.

According to another aspect of the present invention, a method ofoperating a fluid pump includes activating a pump element to draw afluid into a fluid path. The pump element operates to direct a fluid toa position that defines a shadow port having an orifice. The fluid isdivided into a primary flow of the fluid toward an outlet of the fluidpath and an excess flow of the fluid through the orifice and into anaccessory fluid path. The excess flow of the fluid is directed to athermistor. A fluid temperature of the excess flow of the fluid in theaccessory fluid path is measured. The excess flow of the fluid isdirected toward one of an inlet and the outlet of the fluid path.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a first perspective view of a fluid pump incorporating anaspect of the thermistor fluid path;

FIG. 2 is a second perspective view of the fluid pump of FIG. 1;

FIG. 3 is a cross-sectional view of the fluid pump of FIG. 1 taken alongline III-III;

FIG. 4 is a cross-sectional view of the fluid pump of FIG. 3illustrating a flow of a fluid through the thermistor flow path;

FIG. 5 is a perspective view of a printed circuit board (PCB) housingassembly for a fluid pump that incorporates an aspect of the thermistor;

FIG. 6 is a cross-sectional perspective view of the PCB housing assemblyof FIG. 5, taken along line VI-VI; and

FIG. 7 is a schematic flow diagram illustrating a method for operating afluid pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the invention as oriented in FIG. 1. However, itis to be understood that the invention may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventive conceptsdefined in the appended claims. Hence, specific dimensions and otherphysical characteristics relating to the embodiments disclosed hereinare not to be considered as limiting, unless the claims expressly stateotherwise.

As shown in FIGS. 1-6, reference numeral 10 generally refers to aprinted circuit board (PCB) housing assembly for a fluid pump 12 thatincorporates a thermistor 14 for measuring the temperature of fluid 16being passed through the fluid pump 12. The fluid pump 12 includes apump element, such as a generated rotor or gerotor 18, or other similarpositive displacement pump, in communication with an inlet 20 and anoutlet 22 of the fluid pump 12. Activating rotation of the gerotor 18generates a suction 24, or inward pressure, at the inlet 20 that drawsfluid 16 into the fluid path 26 and outward pressure 28 at the outlet 22that pushes fluid 16 out of the fluid path 26. The suction 24 andoutward pressure 28 generated through operation of the gerotor 18cooperate to move the fluid 16 through the fluid path 26. An accessoryfluid path 30, which defines a portion of the fluid path 26, is disposedin communication with the inlet 20 and outlet 22. The accessory fluidpath 30 includes the thermistor 14 that is placed in communication withfluid 16 flowing through the accessory fluid path 30. The thermistor 14is adapted to monitor a temperature of the fluid 16 moving through theaccessory fluid path 30 of the fluid pump 12.

Referring again to FIGS. 1-6, a fluid pump 12, such as an electric oilpump, generally provides lubrication and cooling to various mechanisms,such as a gear box, differential unit, or other similar mechanism. Thefluid pump 12, typically in the form of a gerotor 18, brushless DC(BLDC) electric motor, and a controller can be fully integrated into ahousing assembly that manages the sealing, thermal transfer and partassembly for the electric fluid pump 12. The fluid pump 12 can include arotor 40 and stator 42 that make up the motor 44 for the fluid pump 12.A drive shaft 46 is driven by rotation of the rotor 40 and serves torotate the gerotor 18 for generating the suction 24 and outward pressure28 for moving fluid 16 through the fluid path 26 and, in turn, theaccessory fluid path 30.

Referring again to FIGS. 1-6, the accessory fluid path 30, in the formof a thermistor flow path 50, serves to provide a fluid pump 12 with atemperature sensing functionality for providing real time measurementsregarding fluid temperature during operation of the fluid pump 12. Thetemperature sensor can be a thermistor-style leaded component that isinstalled in the same cavity as the rotor assembly 52 that serves todrive the gerotor 18. Typically, this cavity is “wet” as the rotor 40 issubmerged in fluid 16, such as oil. Within the fluid pump 12, the fluid16 moving through the gerotor 18 flows through an outlet shadow port 60having an orifice 62 that helps to regulate and divide the flow of fluid16 through the fluid path 30 of the fluid pump 12, as will be describedmore fully below.

The fluid 16 is divided between a regulated primary flow 54 of the fluid16 and the remaining fluid 16 that defines an excess flow 56 of thefluid 16. In regulating the flow of fluid 16 from the outlet shadow port60 and orifice 62, the primary flow 54 is a predetermined amount of thefluid 16 that is directed to the outlet 22. By dividing the fluid 16,the excess flow 56 of fluid 16 that is not part of the regulated primaryflow 54 of the fluid 16 is directed through the orifice 62 and into theaccessory fluid path 30. In this manner, the gerotor 18 pushes theprimary flow 54 of the fluid 16 through the outlet 22 and simultaneouslypushes the excess flow 56 of the fluid 16 through the orifice 62 andinto the accessory fluid path 30. Directing the movement of the excessflow 56 of fluid 16 helps to ensure that there is a continuous orsubstantially continuous flow of fluid 16 across the thermistor 14.Additionally, this configuration of the accessory fluid path 30 inrelation to the outlet shadow port 60 and orifice 62 also helps toensure that the temperature of the excess flow 56 of the fluid 16 is atleast substantially similar to the primary flow 54 of fluid 16 that isdirected through the outlet 22. This configuration helps to provide realtime or substantially real time temperature measurements of the fluid16.

In this disclosed device, the accessory fluid path 30 is placed incommunication with the outlet shadow port 60 through the orifice 62 thatcontrols the excess flow 56 of the fluid 16 from the outlet shadow port60 and into the accessory fluid path 30. From the orifice 62 at theoutlet shadow port 60, the excess flow 56 of fluid 16 flows around atleast a portion of the rotor assembly 52, but within the housing 64 ofthe fluid pump 12. After passing along the side 66 of the rotor assembly52, the excess flow 56 of fluid 16 is directed along an inner surface 68of the PCB housing assembly 10 where the thermistor 14 is located. Theinner surface 68 of the PCB housing assembly 10 includes contours 70that are configured to direct the excess flow 56 of fluid 16 from thesides 66 of the rotor assembly 52 along the contours 70, into engagementwith the thermistor 14, and to a central portion 72 of the PCB housingassembly 10. In this manner, the contours 70 and central portion 72 ofthe inner surface 68 of the PCB housing assembly 10 at least partiallydefines the thermistor flow path 50 and the accessory fluid path 30. Thecentral portion 72 of the PCB housing assembly 10 is in communicationwith a channel 80 of the drive shaft 46. This channel 80 of the driveshaft 46 extends through the center of the drive shaft 46 and the rotorassembly 52 and up through the gerotor 18 and to a recirculation path 82that recombines the excess flow 56 of the fluid 16 with fluid 16entering the inlet 20. In this manner, the excess flow 56 of the fluid16 is draw back into the inlet 20 by the suction 24 generated by thegerotor 18. The recombined fluid 16 is then delivered via the gerotor 18and is divided into the primary and excess flows 54, 56 of fluid 16 asdescribed above. In this configuration, a portion of the excess flow 56upon leaving the recirculation path 82 may be divided again as part ofthe excess flow 56. It is contemplated that the excess flow 56 from therecirculation path 82 will be sufficiently mixed with the fluid 16entering the inlet 20. Accordingly, the amount of the excess flow 56that is divided again into a portion of the excess flow 56 issubstantially minimal. The effects of a portion of the excess flow 56being directly recirculated again through the accessory fluid path 30 aspart of the excess flow 56 will have minimal effects on the temperaturemeasurements of the thermistor 14.

In various embodiments, the recirculation path 82 may direct the excessflow 56 of fluid 16 from the accessory fluid path 30 to the outlet 22 ofthe fluid pump 12. In this manner, the excess flow 56 can be at leastpartially re-combined with the primary flow 54 of fluid 16 that is movedthrough the outlet 22.

Referring again to FIGS. 1-6, the return path of the fluid 16 within theaccessory fluid path 30 and through the central channel 80 of the driveshaft 46 forces the excess flow 56 of the fluid 16 to flow directly overthe thermistor 14. Accordingly, temperature measurements of the excessflow 56 of the fluid 16 moving through the thermistor flow path 50 canbe taken by the thermistor 14 in real time or substantially in realtime. The amount of fluid 16 moving through the accessory fluid path 30is controlled by the size of the orifice 62 on the high pressure side ofthe fluid path 26. Additionally, the return path of the accessory fluidpath 30 is at a lower restriction to prevent a pressure build-up withinthe motor cavity. In order to deliver the signal from the thermistor 14within the PCB housing assembly 10, terminals 90 are used to connect thethermistor 14 to the PCB housing assembly 10. These terminals 90 aresealed to prevent leaking into the PCB cavity 92 on the opposite side 66of the thermistor 14.

Within conventional fluid pumps 12, very little fluid 16 is moved in andaround the motor cavity. As such, placing a thermostat or othertemperature sensing device within this area provides little, if any,temperature-related information.

Referring again to FIGS. 1-6, the accessory fluid path 30 that providesthe thermistor flow path 50 provides a convenient and accurate mechanismfor measuring the temperature of the fluid 16 flowing through the fluidpump 12 while not diminishing the performance of the fluid pump 12.

It is contemplated that the fluid pump 12 described herein can be usedin various applications that can include, but are not limited to, fuelpumps, oil pumps, water pumps, combinations thereof, and other fluidpumps 12 that may be submerged or non-submerged.

It is contemplated that the PCB housing assembly 10 and terminals 90 canbe incorporated within new pumps or can be manufactured for installationwith after-market pumps.

Having described various aspects of the device, a method 400 isdisclosed for operating the fluid pump 12. This method 400 includes step402 of activating a pump element to draw a fluid 16 into a fluid path26. The pump element operates to direct a fluid 16 to a position thatdefines a shadow port 60 (step 404). The fluid 16 is divided into aprimary flow 54 of the fluid 16 toward an outlet 22 of the fluid path 26and an excess flow 56 of the fluid 16 through an orifice of the shadowport 60 and into an accessory fluid path 30 (step 406). The excess flow56 of the fluid 16 is directed to a thermistor 14 (step 408). A fluidtemperature of the excess flow 56 of the fluid 16 in the accessory fluidpath 30 is measured (step 410). The excess flow 56 of the fluid 16 isdirected toward the inlet 20 of the fluid path 26 (step 412).

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent invention, and further it is to be understood that such conceptsare intended to be covered by the following claims unless these claimsby their language expressly state otherwise.

What is claimed is:
 1. A fluid pump comprising: a pump elementpositioned within a housing and in communication with an inlet and anoutlet, wherein rotation of the pump element via a motor having a rotorand a stator generates a suction at the inlet and pressure at theoutlet, and wherein the suction and pressure cooperate to move a fluidthrough a fluid path; an accessory fluid path in communication with theinlet and the outlet, wherein the pump element separates the fluid pathfrom the accessory fluid path via an orifice that regulates flow of thefluid into the accessory fluid path, wherein the accessory fluid pathincludes a thermistor in communication with the accessory fluid path,and wherein the thermistor monitors a temperature of the fluid withinthe accessory fluid path, and wherein the accessory fluid path flowsbetween the rotor and an outer wall of the housing and in directengagement with the rotor and the stator and along one side of the outerwall; and a circuit board housing assembly having a contoured portionthat aligns with the one side of the outer wall and the orifice wherein:the accessory fluid path includes a low-restriction return path thatgenerates a continuous flow of the fluid through the accessory fluidpath during operation of the pump element; the continuous flow isdirected between the orifice and the contoured portion and along the oneside of the outer wall and between the rotor and the stator; thelow-restriction return path and the aligned orifice and contouredportion are configured to maintain the temperature of the continuousflow of the fluid in the accessory fluid path substantially similar to atemperature of the fluid in the fluid path; and the thermistor ispositioned in communication with the contoured portion to simultaneouslymonitor, in real time, the temperature of the continuous flow of thefluid in the accessory fluid path and the temperature of the fluid inthe fluid path.
 2. The fluid pump of claim 1, wherein the accessoryfluid path extends from the pump element and around at least a portionof a rotor that drives the pump element to the thermistor, and whereinthe contoured portion of the accessory fluid path is positioned to oneside of the housing and is fluidly connected with a central channel of adrive shaft of the rotor.
 3. The fluid pump of claim 2, wherein thecentral channel of the drive shaft extends through a portion of the pumpelement.
 4. The fluid pump of claim 1, wherein the pump element is apositive displacement pump.
 5. The fluid pump of claim 4, wherein thepositive displacement pump is a generated rotor.
 6. The fluid pump ofclaim 1, wherein the pump element includes an outlet regulating portthat regulates a flow of the fluid through the outlet and through theaccessory fluid path.
 7. The fluid pump of claim 6, wherein the pumpelement and the outlet regulating port regulates a predetermined amountof the fluid into a primary flow of the fluid through the outlet,wherein an amount of the fluid in excess of the predetermined amountdefines an excess flow of the fluid that is directed through the outletregulating port and the orifice and into the accessory fluid path.
 8. Afluid pump comprising: a positive displacement pump element incommunication with a fluid path, the positive displacement pump elementoperated by a motor having a rotor and stator disposed within a housing;an accessory fluid path that defines a portion of the fluid path,wherein the positive displacement pump element separates the accessoryfluid path from a primary portion of the fluid path, the accessory fluidpath flowing from a high-pressure Inlet to a low-restriction return aregulating port in communication with the positive displacement pumpelement, wherein the positive displacement pump element and theregulating port regulate a flow of a fluid between a primary flow of thefluid through the primary portion and to an outlet, and an excess flowof the fluid to the accessory fluid path; and a circuit board housingassembly having a contoured portion aligned with the regulating port andthat includes a thermistor in communication with the accessory fluidpath; wherein operation of the positive displacement pump element inconjunction with the regulating port promotes the primary flow of thefluid toward the outlet and simultaneously promotes the excess flow ofthe fluid through the accessory fluid path having a portion that extendsbetween the rotor and an outer wall of the housing, and within an openspace defined between the rotor and the stator; the excess flow of thefluid through the accessory fluid path defines a directed and continuousflow of the excess flow of the fluid alone one side of the housing andbetween the regulating port and the contoured portion; and thethermistor measures a fluid temperature of the excess flow of the fluidwithin the accessory fluid path, the fluid temperature of the excessflow of the fluid being substantially similar to the fluid temperatureof the primary flow of the fluid.
 9. The fluid pump of claim 8, whereinthe positive displacement pump element generates an inward pressure atan inlet of the fluid path and generates an outward pressure at theoutlet of the fluid path.
 10. The fluid pump of claim 8, wherein thepositive displacement pump element is a generated rotor.
 11. The fluidpump of claim 8, wherein the regulating port includes an orifice thatregulates the excess flow of the fluid into the accessory fluid path,wherein the portion of the accessory fluid path is configured such thatthe fluid directly engages the rotor and the stator within the housing.12. The fluid pump of claim 8, wherein the accessory fluid path extendsfrom the positive displacement pump element and around at least aportion of the rotor of the motor to the thermistor, and wherein theaccessory fluid path extends from the thermistor and through a centralchannel of a drive shaft of the motor.
 13. The fluid pump of claim 12,wherein the thermistor is positioned on the circuit board housingassembly and within the accessory fluid path, and wherein the circuitboard housing assembly defines a portion of the accessory fluid paththat directs the excess flow of the fluid from the rotor, across thethermistor and to the central channel.
 14. The fluid pump of claim 12,wherein the central channel of the drive shaft extends through a portionof the positive displacement pump element and toward an inlet of thefluid path.
 15. The fluid pump of claim 8, wherein the positivedisplacement pump element and the regulating port regulate apredetermined amount of the fluid into the primary flow of the fluidthrough the outlet, wherein an amount of the fluid in excess of thepredetermined amount defines the excess flow of the fluid that isdirected through the regulating port and into the accessory fluid path.